Figured it out - the permission on the menu item had 2 Civi permissions using the OR operator. When I switched it to AND operator, I can now see the "Find and Merge Duplicates" menu item!

So I am able to see the rules when I go directly to that url. When I go to the navigation I see the find and merge duplicates listed under contacts, but it still doesn't show in my menu. Very strange - can I share an image on here?

Thanks! I am an administrator so do have both those permissions on my account, but I still don't see the menu option "Contacts > Find and Merge Duplicate Contacts". I was able to see the merge contacts options from the search results page.